Dry razor with removable cutting head



July 25, 1967 e. KRATZ DRY RAZOR WITH REMOVABLE CUTTING HEAD 2 Sheets-Sheet l Filed July 22, 1965 FIG.

H H II I H u ll l u V II u q l' m 'I' u |I I' m I n H I 56 40 54 48 4 Q GERD R FIG. 2 BY A TTORNE Y6 United States Patent 3,332,146 DRY RAZOR WITH REMOVABLE CUTTING HEAD Gerd Kratz, Augustastrasse 35, Solingen, Germany Filed July 22, 1965, Ser. No. 495,367 Claims priority, application Germany, July 23, 1964, K 53,546 3 Claims. (Cl. 3043.92)

Dry razors with removable cutting heads are known in Various forms. In one known form the cutting head consists of head housing with cutting foil, this being held in the cutting head housing by means of clamping bars, and a movable cutting block which has a driver assembled on the drive pin of the motor. In this known form the cutting block is supported on the clamping bar in the vicinity of its two ends by means of helical springs. On one hand, this is useful with respect to assemblage, but, on the other hand, the springs are annoying in cleaning the shaving head. It is, moreover, also disadvantageous from the functional view. Actually, due to the oscillation during operation the helical spring is displaced from its axis with the result that the cutting block does not exert a normal (vertical) force on the entire cutting foil. In addition, the forces resulting from oscillation are considerable. As a result, after careless cleaning of the helical spring or the clamping bar there is deformation, which is harmful to the pressure. An imperfect cutting action, particularly near the edges of the cutting block, usually result. The invention will prevent these objections.

The invention relates to a dry razor with a head, which is removable from the housing, with the cutting foil, and a removable cutting block held in the housing by means of a clamping pin, this block having a driver mounted on the drive pin of the motor. The invention consists in the fact that the cutting block is looselylwith considerable play) located in the head housing and secured by the clamping bar from falling out when the head is removed, as well as by a spring of the drive pin which is pressed against the cutting foil.

Specifically, the invention relates to different ways of carrying this out and to the article made therefrom. One example of the invention is characterized by the fact that the driver has a funnel-shaped opening for the drive pin of the drive wheel, and the diameter of the funnelshaped opening is large enough so that even with the displacement of the cutting block under the cutting foil, and the action of the drive pin, the pin always remains secure in the opening.

The said spring can be assembled, in the dry razor of the invention, on the drive pin in such a way that it is supported with the head on the driver of the head. It can, thereby, be essentially loosely set against the drive pin. A preferred form of the invention is characterized in this way by the fact that the spring is assembled on the drive pin and is fixed by means of adjustable disc wheels and holding pins, or the like, on the drive pin. The clamping bar is suitably constructed, in the dry razor of the invention, as a steel leaf spring and is inserted, on one hand, into the housing, and on the other, is held securely in the housing.

The advantages attained by the invention are primarily to be seen with respect to the function by the fact that With the dry razor of the invention, the pressure is exerted on the cutting head perpendicular to the cutting foil, and has constant force with the movement of the cutting head. Even with improper cleaning, pressure does not Vary. The result attained by this invention is optimum cutting action even after a long period of operation. Moreover, with the dry razor of the invention, the assembly of the cutting block and the head as well as the spring is very simple, since it requires only the placement of the spring on the drive pin. Finally, the cutting head can be easily cleaned by removing the cutting block While the cutting block can be directly exchanged for another piece such as a massage piece, another cutting head, etc.

The invention is more completely described in the drawing which is shown only as an example; it shows:

FIGURE 1 is an end elevation, partially broken away in section, and on an enlarged scale, of the electric shaver of the invention;

FIGURE 2 is a longitudinal vertical cross sectional view taken substantially on line 2-2 of FIGURE 1;

FIG. 3 is a perspective view, partially broken away, particularly illustrating the cutting block and the clamping bar utilized to secure the cutting block in the head housing; and

FIG. 4 is a perspective view of the saddle which holds the cutting block in the head housing.

In the drawings, the shaver described is of the type generally illustrated in British Patent No. 534,069, but incorporating improvement features. The numeral 10 in FIGURE 1 indicates generally the casing or housing of a shaver which contains a motor 11 turned on and off by a switch 12, the motor serving to oscillate back and forth rapidly a shaft or drive pin 14. The casing 10 includes an integral upwardly extending flange 16 to which is removably secured by spring or ball detents 18 a head indicated as a whole by the numeral 20.

The head 20 normally comprises an endless plastic ring engaging with the upper end of the casing 10 and removably secured to the casing 10 by means of the spring or ball detents 18 previously described. The plastic ring has secured thereto a metal foil or screen 22, as by screws 24, the foil 22 having the standard substantially semi-cylindrical contour.

Carried in the cutter head 20 is a cutter block indicated as a Whole by the numeral 26, this being formed from a plurality of cutter blades 28 held in parallel relation on a plurality of tubes 30, as by brazing.

The cutter block 26 is loosely held in relationship with foil 22 by means of a C-shaped or O-shaped frame or clamping bar 32 hinged at 34 to the head 20 and re movably secured at the opposite side of the head by spring detent or ball means 36. The frame 32 thus provides spring-like portions extending as best seen in FIG- URE 2 under the cutter block to hold it in loose position against the foil 22, but with the frame 32 being swingable out of the way upon the removal of the head 20 from the casing 10 to facilitate the cleaning of the foil and the cutter block.

Means are also provided for holding the cutter block 26 quite snugly against the inside of the foil 22 during the actual shaving operation, and for connecting the oscillating pin 14 or shaft of the motor to the cutter block 26. For this purpose a driver assembly basically comprised of a plastic saddle or driver assembly is provided, and is indicated as a whole by the numeral 40. The saddle 40 has a pair of fingers 42 which extend up and grip the cutter block 26. Also the saddle 40 is formed at its lower surface with a conical opening 44 which receives a conical washer 46 which engages with the top of a compression spring 48 the lower end of which contacts a plate 50 mounted in the casing 10. The spring 48 is compressed somewhat with the head 20 in position on the casing 10, and the compression of the spring 48 acting through the washer 46 and the saddle 40 holds the cutter block 26 snugly against the inside of the foil 22 to achieve the best cutting action between the plates 28 and the foil, but yet permitting reciprocation of the cutter block 26 in the direction of the arrow 52 seen in FIGURE 2.

The saddle 40 is formed with a central hole through which the shaft 14 extends, and this central hole is provided with circumferentiaily spaced slots 54 through which slots lugs 56 on the end of shaft 14 can "be moved. The provision of the apparatus just described allows the parts to function during the shaving operation in the position seen in FIGURE 1 of the drawings, but when the head 20 is removed from the casing the lugs 56 on the end of the shaft 14 move axially down through the slots 54 in the saddle 40 to allow the head 20 to be removed from the casing 10. As the saddle 40 moves vertically away from the washer 46 the washer moves up to strike the lugs 56 on the shaft 14, with the spring 48 somewhat expanding, thus leaving the washer 46 and the spring 48 on the shaft 14 of the casing 10 as the head 20 is removed.

The cleaning of the removed head 20 is now simplified by swinging the frame 32 about the pivot 34 to remove the cutter block 26, all as aforesaid. The reassembly of the apparatus involves merely the reversal of the operations described.

What is claimed is:

1. In a dry razor, the combination of a housing,

a head removably secured to the housing,

a cutting foil carried in the head,

a cutter block loosely located in the head,

a clamping bar means hingedly connected to one side of the head and removably secured at the opposite side of the head to prevent the cutter block from falling out of the head when the head is removed from the housing,

a motor,

a drive pin driven in oscillation by the motor,

a helically wound vertically positioned compression spring means received over the drive pin and *being fixedly positioned at its lower end, and

driver assembly means, including a saddle member having a bottom surface and a center vertically extending bore, operatively connecting said drive pin to said cutter block, said driver assembly means engagmg and supporting substantially the entire central portion of the cutter block, said driver assembly means having a pair of spaced, upwardly extending integral fingers which grip the cutter block, the center portion of the bottom surface of said driver assembly means at said bore being of frusto-conical shape to provide a conical surface that operatively receives and centers the free end of said compression spring means whereby the compression spring means acting through said driver assembly means exerts pressure on the entire cutter block perpendicular to the cutting foil during reciprocation of said cutter block, and wherein the drive pin engages said center bore of the driver assembly means to transfer the reciprocating motion of the pin to the assembly means.

2. The combination according to claim 1 whereby said drive pin has a plurality of integral radially extending lugs on the outer end thereof, and the vertically extending bore of the driver assembly means forms a central hole through which the pin extends, the driver assembly means having circumferentially spaced slots through which the lugs on the drive pin are moved as the driver assembly means and the cutter block are removed from the housing.

3. The combination according to claim 2 wherein the driver assembly means includes a washer slidably positioned on said drive pin and received within the conical opening in the bottom surface of said driver assembly, which washer engages the free end of said compression spring means to allow the spring means to bias said driver assembly upwardly, said washer holding said spring means on said drive pin when said driver assembly means is removed from the housing.

References Cited UNITED STATES PATENTS 2,105,775 1/1938 Nilson 30-4392 2,107,207 2/1938 Muros 30-4392 2,177,440 10/1939 Muros 3043.92 2,562,104 7/1951 Kobler et al 30-4392 2,600,658 6/1952 Knopp 30-4392 2,900,719 8/1959 Kohner et al. 30-4392 2,930,119 3/1960 Kleinman 30-4392 3,045,346 7/1962 Akerib 30-4392 3,105,298 10/1963 Carissimi 30-4392 3,172,200 3/1965 Ream 30-431 3,191,299 6/1965 Locke 30-4392 FOREIGN PATENTS 1,174,958 11/1958 France.

825,518 12/1959 Great Britain.

WILLIAM FELDMAN, Primary Examiner.

MYRON C. KRUSE, Examiner. 

1. IN A DRY RAZOR, THE COMBINATION OF A HOUSING, A HEAD REMOVABLY SECURED TO THE HOUSING, A CUTTING FOIL CARRIED IN THE HEAD, A CUTTER BLOCK LOOSELY LOCATED IN THE HEAD, A CLAMPING BAR MEANS HINGEDLY CONNECTED TO ONE SIDE OF THE HEAD AND REMOVABLY SECURED AT THE OPPOSITE SIDE OF THE HEAD TO PREVENT THE CUTTER BLOCK FROM FALLING OUT OF THE HEAD WHEN THE HEAD IS REMOVED FROM THE HOUSING, A MOTOR, A DRIVE PIN DRIVEN IN OSCILLATION BY THE MOTOR, A HELICALLY WOUND VERTICALLY POSITIONED COMPRESSION SPRING MEANS RECEIVED OVER THE DRIVEN PIN AND BEING FIXEDLY POSITIONED AT ITS LOWER END, AND DRIVER ASSEMBLY MEANS, INCLUDING A SADDLE MEMBER HAVING A BOTTOM SURFACE AND A CENTER VERTICALLY EXTENDING BORE, OPERATIVELY CONNECTING SAID DRIVE PIN TO SAID CUTTER BLOCK, SAID DRIVER ASSEMBLY MEANS ENGAGING AND SUPPORTING SUBSTANTIALLY THE ENTIRE CENTRAL PORTION OF THE CUTTER BLOCK, SAID DRIVER ASSEMBLY MEANS HAVING A PAIR OF SPACED, UPWARDLY EXTENDING INTEGRAL FINGERS WHICH GRIP THE CUTTER BLOCK, THE CENTER PORTION OF THE BOTTOM SURFACE OF SAID DRIVER ASSEMBLY MEANS AT SAID BORE BEING OF FRUSTO-CONICAL SHAPE TO PROVIDE A CONICAL SURFACE THAT OPERATIVELY RECEIVES AND CENTERS THE FREE END OF SAID COMPRESSION SPRING MEANS WHEREBY THE COMPRESSION SPRING MEANS ACTING THROUGH SAID DRIVER ASSEMBLY MEANS EXERTS PRESSURE ON THE ENTIRE CUTTER BLOCK PERPENDICULAR TO THE CUTTING FOIL DURING RECIPROCATION OF SAID CUTTER BLOCK, AND WHEREIN THE DRIVE PIN ENGAGES SAID CENTER BORE OF THE DRIVER ASSEMBLY MEANS TO TRANSFER THE RECIPROCATING MOTION OF THE PIN TO THE ASSEMBLY MEANS. 